A parallel-flow type heat exchanger is available as a type of heat exchanger. This heat exchanger includes a pair of header pipes and a plurality of flat tubes provided between the header pipes, and is configured such that a fluid flowing into one of the headers passes through the plurality of flat tubes and flows out into the other header pipe.
In this parallel-flow type heat exchanger, when the pair of header pipes are disposed so as to be oriented in a vertical direction, liquid refrigerant in a gas-liquid two phase refrigerant is likely to flow into the flat tubes positioned therebelow due to the effects of gravity, making it difficult to control the refrigerant flowing through the plurality of flat tubes to a uniform flow rate. In a top-flow type heat exchanger in particular, such as a multi air conditioner for a building, an air flow increases steadily upward toward the blower, and since the flow rate of the refrigerant cannot be increased in a location with a high air flow, the heat exchanger cannot be utilized effectively.
Hence, to reduce the effects of gravity among the plurality of flat tubes, a parallel-flow type heat exchanger may be configured such that the pair of header pipes are disposed horizontally.
Meanwhile, an existing outdoor unit of an air conditioner may be configured such that heat exchange sections are disposed on a plurality of surfaces of a casing of the outdoor unit. Here, when an attempt is made to cause a parallel-flow type heat exchanger in which the pair of header pipes are disposed horizontally, as described above, to function on a plurality of surfaces of the casing of the outdoor unit, the header pipes must be bent in alignment with the plurality of surfaces. However, bending a header pipe into an L shape or an angled C shape, for example, requires a large load, leading to increases in device size and cost.
A heat exchanger disclosed in PTL 1, for example, is available in relation to this problem. In the heat exchanger disclosed in PTL 1, the heat exchanger is divided into a plurality of blocks, and the plurality of divided blocks are disposed in a horizontal direction.